ABSTRACT
The present study aimed to examine the effect of interleukin (IL)-4 on neutrophil chemotaxis in airway inflammation in asthmatic rats and the possible mechanism. Male Wistar rats were intranasally instilled with recombinant rat (rr) IL-4 (rrIL-4) at different doses [2, 4 or 8 μg/animal, dissolved in 200 μL normal saline (NS)] or rrIL-4 at 4 μg/animal (dissolved in 200 μL NS). NS (200 μL) and LPS (6 mg/kg/animal, dissolved in 200 μL NS) were intranasally given respectively in the negative and positive control groups. Moreover, the asthmatic lung inflammation was induced in rats which were then intranasally treated with rrIL-4 (4 μg/animal) or LPS (6 mg/kg/animal). The normal rats treated with different doses of rrIL-4 and those asthmatic rats were sacrificed 6 h later. And animals instilled with rrIL-4 at 4 μg were sacrificed 6, 12 or 24 h later. The bronchoalveolar lavage fluid (BALF) and lungs were harvested for detection of leukocyte counts by Wright-Giemsa staining and lung histopathology by haematoxylin-eosin (HE) staining. The levels of cytokine-induced neutrophil chemoattractant (CINC)-1 and intercellular adhesion molecule (ICAM)-1 in BALF were determined by ELISA. Real-time PCR was used to measure the mRNA expression of CINCs (CINC-1, CINC-2α, CINC-2β, CINC-3) and ICAM-1 in lung tissues. The results showed that the intranasal instillation of IL-4 did not induce a recruitment of neutrophils in BALF in rats. However, IL-4 could increase the CINC-1 level in BALF in a dose-dependent manner at 6 h. But the mRNA expression levels of CINC-1, CINC-2α, CINC-2β, CINC-3 were not significantly increased in lungs of IL-4-treated rats relative to NS negative control group. Moreover, IL-4 was found to augment the mRNA expression of ICAM-1 in lungs and the ICAM-1 level in BALF at 6 h. However, the increase in CINC-1 and ICAM-1 levels in BALF of IL-4-treated asthmatic rats was not significantly different from that in untreated asthmatic rats. These findings indicate that IL-4 does not directly recruit neutrophils in the rat lungs, but it may contribute to airway neutrophilia through up-regulation of CINC-1 and ICAM-1.
Subject(s)
Animals , Male , Rats , Asthma , Allergy and Immunology , Chemotactic Factors , Allergy and Immunology , Intercellular Adhesion Molecule-1 , Allergy and Immunology , Interleukin-4 , Allergy and Immunology , Lung , Allergy and Immunology , Neutrophils , Allergy and Immunology , Rats, WistarABSTRACT
In order to study whether cysteine-rich 61 protein (cyr61) is involved in the pathogenesis of asthma and its relation to airway inflammation, the effect of dexamethasone (Dxm) on the expression of cyr61 in the lung tissues of asthmatic mice was investigated. Forty BALB/c mice were divided into asthma group (n=15), control group (n=10) and Dxm group (n=15). The asthma group was sensitized and challenged by ovalbumin (OVA). The mice in Dxm group were intraperitoneally administered with Dxm after OVA challenge. The expression of cyr61 in the lung tissues was detected by using immunohistochemistry, and that of eotaxin protein in the bronchoalveolar lavage fluid (BALF) by using enzyme-linked immunosorbent assay (ELISA). The number of inflammatory cells in BALF was also analyzed. The results showed that the cyr61 expression was highest in asthma group (P<0.05), followed by Dxm group (P<0.05) and control group. The cyr61 had a positive correlation with the total nucleated cells (r=0.867, P<0.05), especially eosinophils (r=0.856, P<0.05), and eotaxin level (r=0.983, P<0.05) in the BALF. Our findings suggested that cyr61 is expressed in airway epithelial cells and has a positive correlation with eotaxin and number of airway infiltrating eosinophils.
Subject(s)
Animals , Female , Mice , Anti-Inflammatory Agents , Pharmacology , Asthma , Drug Therapy , Metabolism , Bronchoalveolar Lavage Fluid , Chemistry , Cell Biology , Chemokines, CC , Metabolism , Cysteine-Rich Protein 61 , Dexamethasone , Pharmacology , Enzyme-Linked Immunosorbent Assay , Epithelial Cells , Metabolism , Pathology , Immunohistochemistry , Injections, Intraperitoneal , Leukocyte Count , Lung , Metabolism , Pathology , Mice, Inbred BALB C , Neutrophils , Pathology , OvalbuminABSTRACT
The present study aimed to examine the effect of interleukin (IL)-4 on neutrophil chemotaxis in airway inflammation in asthmatic rats and the possible mechanism. Male Wistar rats were intranasally instilled with recombinant rat (rr) IL-4 (rrIL-4) at different doses [2, 4 or 8 μg/animal, dissolved in 200 μL normal saline (NS)] or rrIL-4 at 4 μg/animal (dissolved in 200 μL NS). NS (200 μL) and LPS (6 mg/kg/animal, dissolved in 200 μL NS) were intranasally given respectively in the negative and positive control groups. Moreover, the asthmatic lung inflammation was induced in rats which were then intranasally treated with rrIL-4 (4 μg/animal) or LPS (6 mg/kg/animal). The normal rats treated with different doses of rrIL-4 and those asthmatic rats were sacrificed 6 h later. And animals instilled with rrIL-4 at 4 μg were sacrificed 6, 12 or 24 h later. The bronchoalveolar lavage fluid (BALF) and lungs were harvested for detection of leukocyte counts by Wright-Giemsa staining and lung histopathology by haematoxylin-eosin (HE) staining. The levels of cytokine-induced neutrophil chemoattractant (CINC)-1 and intercellular adhesion molecule (ICAM)-1 in BALF were determined by ELISA. Real-time PCR was used to measure the mRNA expression of CINCs (CINC-1, CINC-2α, CINC-2β, CINC-3) and ICAM-1 in lung tissues. The results showed that the intranasal instillation of IL-4 did not induce a recruitment of neutrophils in BALF in rats. However, IL-4 could increase the CINC-1 level in BALF in a dose-dependent manner at 6 h. But the mRNA expression levels of CINC-1, CINC-2α, CINC-2β, CINC-3 were not significantly increased in lungs of IL-4-treated rats relative to NS negative control group. Moreover, IL-4 was found to augment the mRNA expression of ICAM-1 in lungs and the ICAM-1 level in BALF at 6 h. However, the increase in CINC-1 and ICAM-1 levels in BALF of IL-4-treated asthmatic rats was not significantly different from that in untreated asthmatic rats. These findings indicate that IL-4 does not directly recruit neutrophils in the rat lungs, but it may contribute to airway neutrophilia through up-regulation of CINC-1 and ICAM-1.
ABSTRACT
In order to study whether cysteine-rich 61 protein (cyr61) is involved in the pathogenesis of asthma and its relation to airway inflammation, the effect of dexamethasone (Dxm) on the expression of cyr61 in the lung tissues of asthmatic mice was investigated. Forty BALB/c mice were divided into asthma group (n=15), control group (n=10) and Dxm group (n=15). The asthma group was sensitized and challenged by ovalbumin (OVA). The mice in Dxm group were intraperitoneally administered with Dxm after OVA challenge. The expression of cyr61 in the lung tissues was detected by using immunohistochemistry, and that of eotaxin protein in the bronchoalveolar lavage fluid (BALF) by using enzyme-linked immunosorbent assay (ELISA). The number of inflammatory cells in BALF was also analyzed. The results showed that the cyr61 expression was highest in asthma group (P<0.05), followed by Dxm group (P<0.05) and control group. The cyr61 had a positive correlation with the total nucleated cells (r=0.867, P<0.05), especially eosinophils (r=0.856, P<0.05), and eotaxin level (r=0.983, P<0.05) in the BALF. Our findings suggested that cyr61 is expressed in airway epithelial cells and has a positive correlation with eotaxin and number of airway infiltrating eosinophils.